The inventive concept relates generally to electronic data storage technologies. More particularly, certain embodiments of the inventive concept relate to memory devices and methods that adjust read voltages according to varying threshold voltage distributions of memory cells.
There is a general demand, in many fields of electronics, to produce components with reduced size and higher performance. In the field of electronic data storage technologies, in particular, there is a demand for memory devices having smaller memory cells, higher storage capacity, faster access time, and lower power consumption, among other things.
In an effort to produce nonvolatile memory devices with relatively small size and high storage capacity, researchers have developed technologies and techniques for storing more than one bit of data per memory cell. In general, a memory device storing more than one bit of data per memory cell can be referred to as a multi-level cell (MLC) memory device. One drawback of storing more than one bit of data per memory cell is that it can reduce the reliability of the memory cells. For instance, in a flash memory device, storing more than one bit of data per memory cell may reduce the margins between adjacent threshold voltage distributions, requiring tighter operating margins and increasing the probability of read or program errors. Accordingly, as researchers continue to develop MLC memory devices, there is a related need to develop techniques and technologies to control the reliability of those devices.